The present invention relates generally to metal wood type golf clubs, and more particularly to such golf clubs wherein the club head has a metallic shell and foam interior and has novel weight distribution providing substantially improved distance, accuracy and consistency over prior metal wood golf clubs.
The concept of metal wood type golf clubs having metallic shell-like or hollow heads is relatively old. See, for example U.S. Pat. No. 1,526,438 to Scott. More recent developments in metal wood type golf club designs have introduced a number of design changes which are alleged to provide improved accuracy, distance and shot consistency. Such developments have included distributing the weight of the metal head so as to enlarge the area of the striking face of the club head which can impact the ball without adversely affecting the flight path imparted to the ball. More particularly, the area of the ball-striking face of the club head about the "sweet spot" which can be impacted by the ball without significantly changing the flight characteristics of the resulting shot is increased. Ideally, the sweet spot, which is determined by the center of mass of the club head, alternatively termed the center of gravity, is located generally centrally on the ball-striking face of the club head. Conventionally, the ball-striking face is defined by a generally planar or somewhat convexly bulged surface having a predetermined loft angle and a plurality of parallel spaced grooves or score lines disposed generally horizontally when the club head is in a normal ball addressing orientation. During play, striking a golf ball off-center from the sweet spot generally adversely affects the distance, direction and spin imparted to the ball, thus affecting the consistency of results between similar shots or hits with a particular metal wood. Further, and a problem particularly encountered by golfers of lower skill level, the club head may rotate about an axis generally parallel to the axis of the club shaft at the moment of impact with a ball, due either to under or over rotation of the golfer's hands, or due to off-center striking of the ball. Such rotation of the club head further reduces the accuracy, distance, trajectory and consistency desired, frequently resulting in slicing or hooking of the ball.